Radiocarbon evidence for alternating northern and southern sources of ventilation of the deep Atlantic carbon pool during the last deglaciation

Skinner, Luke C. and Waelbroeck, Claire and Scrivner, Adam E. and Fallon, Stewart J. (2014) Radiocarbon evidence for alternating northern and southern sources of ventilation of the deep Atlantic carbon pool during the last deglaciation. Proceedings of the National Academy of Sciences, 111 (15). pp. 5480-5484. ISSN 0027-8424, 1091-6490 DOI 10.1073/pnas.1400668111

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Abstract

Recent theories for glacial–interglacial climate transitions call on millennial climate perturbations that purged the deep sea of sequestered carbon dioxide via a “bipolar ventilation seesaw.” However, the viability of this hypothesis has been contested, and robust evidence in its support is lacking. Here we present a record of North Atlantic deep-water radiocarbon ventilation, which we compare with similar data from the Southern Ocean. A striking coherence in ventilation changes is found, with extremely high ventilation ages prevailing across the deep Atlantic during the last glacial period. The data also reveal two reversals in the ventilation gradient between the deep North Atlantic and Southern Ocean during Heinrich Stadial 1 and the Younger Dryas. These coincided with periods of sustained atmospheric CO2 rise and appear to have been driven by enhanced ocean–atmosphere exchange, primarily in the Southern Ocean. These results confirm the operation of a bipolar ventilation seesaw during deglaciation and underline the contribution of abrupt regional climate anomalies to longer-term global climate transitions.

Item Type:	Article
Additional Information:	Copyright © 2014 National Academy of Sciences This paper is made available according to the conditions stated here: http://www.sherpa.ac.uk/romeo/issn/1091-6490/
Uncontrolled Keywords:	2014AREP; IA67;
Subjects:	01 - Climate Change and Earth-Ocean Atmosphere Systems
Divisions:	01 - Climate Change and Earth-Ocean Atmosphere Systems 08 - Green Open Access
Journal or Publication Title:	Proceedings of the National Academy of Sciences
Volume:	111
Page Range:	pp. 5480-5484
Identification Number:	10.1073/pnas.1400668111
Depositing User:	Sarah Humbert
Date Deposited:	05 May 2014 15:30
Last Modified:	13 Jul 2014 17:20
URI:	http://eprints.esc.cam.ac.uk/id/eprint/3046

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